From a2cf06f5f65a3ea36e9369f8a5ec14f86dfa9c32 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 8 Sep 2020 11:18:57 +0800 Subject: [PATCH] bonding: fix a potential double-unregister [ Upstream commit 832707021666411d04795c564a4adea5d6b94f17 ] When we tear down a network namespace, we unregister all the netdevices within it. So we may queue a slave device and a bonding device together in the same unregister queue. If the only slave device is non-ethernet, it would automatically unregister the bonding device as well. Thus, we may end up unregistering the bonding device twice. Workaround this special case by checking reg_state. Fixes: 9b5e383c11b0 ("net: Introduce unregister_netdevice_many()") Reported-by: syzbot+af23e7f3e0a7e10c8b67@syzkaller.appspotmail.com Cc: Eric Dumazet Cc: Andy Gospodarek Cc: Jay Vosburgh Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Yang Yingliang --- drivers/net/bonding/bond_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 76fd5fc437eb..ee7138a92d5e 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2029,7 +2029,8 @@ static int bond_release_and_destroy(struct net_device *bond_dev, int ret; ret = __bond_release_one(bond_dev, slave_dev, false, true); - if (ret == 0 && !bond_has_slaves(bond)) { + if (ret == 0 && !bond_has_slaves(bond) && + bond_dev->reg_state != NETREG_UNREGISTERING) { bond_dev->priv_flags |= IFF_DISABLE_NETPOLL; netdev_info(bond_dev, "Destroying bond %s\n", bond_dev->name); -- GitLab